PITTSBURGH (June 13, 2017) … The advantages of additive manufacturing (AM) – from building complex structures for specific environments to repairing damaged components – continue to be grow as the technology matures. However, there has been limited research in developing new metals and alloys that would further enhance AM processes. Thanks to a three year, $449,000 award from the Office of Naval Research(ONR), the University of Pittsburgh’s Swanson School of Engineering will explore next-generation metals, especially steel, for use in additive manufacturing.

The research, “Integrated Computational Materials Design for Additive Manufacturing of High-Strength Steels used in Naval Environments,” is led by Wei Xiong, PhD, assistant professor in the Swanson School’s Department of Mechanical Engineering and Materials Science. The research team also includes Esta Abelev, PhD and Susheng Tan, PhD as the senior personnel supporting materials microstructure characterization and corrosion tests. Funding is provided by the ONR Additive Manufacturing Alloys for Naval Environments (AMANE) program to design, develop and optimize new metallic alloy compositions for AM that are resistant to the effects of the Naval/maritime environment.

Dr. Xiong in the Swanson School’s ANSYS Additive Manufacturing Laboratory. (Photo courtesy of the University of Pittsburgh’s Swanson School of Engineering)

“There are several metals, from nickel alloys to aluminum and titanium, which are the foundation for AM production of complex parts with properties that could not be developed via traditional, or subtractive, manufacturing. However, many of these materials are not at strong or reliable in the harsh environment of the sea, and that’s a disadvantage for the Navy and other maritime agencies,” Dr. Xiong said. “Steel and its alloys are still the best, most versatile and structurally sound metals for naval construction and repair, and so our research will focus on developing new toolkits to leverage the use of new steel prototypes in AM that will benefit the U.S. Navy.

In particular, the Physical Metallurgy and Materials Design Laboratory led by Dr. Xiong will design a new type of high-strength low-alloy steel, which can be widely used in naval construction. The ONR proposal’s objective is for the Pitt researchers to apply the Integrated Computational Materials Engineering (ICME) tools to design both the composition of these allows and the direct metal laser sintering process, which is used in AM to fuse the metal powders into components. The research will also focus on post-process optimization, which can further improve the mechanical properties and corrosion resistance of these specialty steels.

“Additive manufacturing presents a transformative opportunity for the Navy and Department of Defense to develop complex structures that are stronger, more reliable and yet cost-effective,” Dr. Xiong said. “Through the integrated computational materials design, from metal development to production and final optimization, we believe we will design new types of steel that will greatly benefit the Navy and the women and men who serve.”